Those late-night slumber parties of middle school and joy rides around town with friends in high school might seem silly once you reach adulthood. But according to a new study from Child Development, they matter. In fact, being able to build strong friendships in your younger years may mean you'll be more satisfied with your romantic relationships in the future—and this is a lesson that may be just as important for adults as it is for kids.

The new study, conducted by researchers at the University of Virginia and James Madison University, followed a group of 165 ethnically, racially, and socioeconomically diverse people from ages 13 to 30. The researchers checked in with these people every year to gather reports about the quality of their social and romantic relationships, as well as asking them questions about their closest friends.

After 17 years of observation, the researchers determined that same-gender teenage friendships are something of a testing ground for future romantic partnerships. The authors found that the more relationship skills these kids learned with their friends, the more satisfied they were with their romantic partners once they reached adulthood. They specifically emphasized four skill sets developed through friendships that were the strongest predictors of a satisfying romantic relationship later in life:

Learning how to form and maintain close friendships over the long term

It's easy to see how these skill sets can apply to romantic relationships just as easily as they would in platonic friendships: Being able to stand up for yourself, give your partner the benefit of the doubt, be sociable and able to build intimacy, and being able to maintain that intimacy over time are all keys to a successful relationship of any kind.

Interestingly, the findings also showed teens' romantic relationships had very little association with their future relationship satisfaction. Qualities like sexual experience, dating experience, and physical attractiveness during high school weren't predictors of satisfying relationships at all! (Everyone, breathe a sigh of relief with me now.)

"Romantic relationships in adolescence are much more likely to be fleeting, and as such, they don't appear to be the main way teens learn skills needed for the future," Rachel K. Narr, a doctoral student at the University of Virginia and co-author of the study, said in a news release.

"Instead, it's the skills learned in friendships with peers of the same gender—skills such as stability, assertiveness, intimacy, and social competence—that correspond most closely to the skills needed for success in adult romantic relationships," said Joseph P. Allen, a professor of psychology at the University of Virginia and lead study author.

We all want satisfying romantic relationships, but this study is a great reminder to focus on your friends before you start chasing down romantic partners. We like to think that more relationship experience will correlate to better relationships each time, but this study suggests the skills you build with your friends are the ones that will really sink in and help you figure out how to make love work—maybe because you can work on them earnestly without all the intensity, baggage, rules, and games that come with romance.

Although this particular study focused on teen friendships, the transformative power of friendships even in our adult years has been well-documented by scientific research: Past studies on adult friendships have shown, for example, that sharing secrets with friends can improve our physical and emotional well-being and that talking about sex with friends helps us feel more confident in bed.

If you want to learn how to have a successful relationship, spend some time on your friends. They're the ones who can teach us what real love looks like.